1. Field of the Invention
This invention relates to an improved thermally actuatable electrical switch construction and to a conductive lead therefor as well as to methods of making the same.
2. Prior Art Statement
It is known to provide a thermally actuatable electrical switch construction having a housing means carrying an electrically insulating end plug provided with an opening means passing therethrough and in which a portion of a conductive lead is disposed so that opposed ends of the lead extend beyond opposed ends of the plug and respectively define a fixed contact means inside the housing means and a terminal outside the housing means, the portion of the lead being retained in the opening means by sealing means disposed in the opening means and extending around the portion of the lead and interlocking therewith to tend to prevent axial movement of the lead into the housing means as well as to tend to prevent rotational movement of the lead relative to the end plug.
For example, see the following item:
(1) U.S. Pat. No. 4,060,787--Budnik
It appears that the portion of the lead that is disposed in the opening means of the end plug of the thermally actuatable electrical switch construction of item (1) above is provided with a plurality of radially disposed reliefs deformed into the portion of the lead in a manner to prevent each relief from extending around the entire circumference of the lead so as to cause the sealing means to enter the reliefs and form set blocks of sealing means that tend to prevent axial movement of the lead into the housing means as well as to tend to prevent rotational movement of the lead relative to the end plug.
It is also known to hermetically seal an electrical terminal pin in a sleeve-like opening of a supporting body by means of a molded dielectric sealing member which coacts with the terminal pin and the supporting body.
For example, see the following item:
(2) U.S. Pat. No. 3,770,878--Dozier
It appears that the terminal pin of the arrangement of item (2) above is provided with a plurality of axially disposed shoulders to provide means for coacting with the molding material to tend to prevent axial movement therebetween (see column 5, lines 24-26) and is provided with a roughened surface or a knurled surface on an annular reduced portion thereof to tend to prevent rotational movement therebetween (see column 5, lines 35 and 36).